1. Field of the Invention
This invention relates to solid dosage forms and sustained release excipient materials, particularly those including konjac.
2. Statement of Related Art
Sustained release excipients are compositions that enable drug release over a period of time on a predetermineable basis. They are incorporated into formulations containing active ingredients to provide a sustained release of those active ingredients from the formulation. Typically, sustained release excipients are incorporated in a solid dosage form such as a pharmaceutical tablet which is designed to release the active ingredient over an extended time period.
Konjac (Amorphophallus konjac) is a plant, the tuber of which is the source of a well-known foodstuff in China and Japan, namely konjac flour. This flour, which contains a variety of insoluble materials described below as well as a major amount of desirable water-soluble substances, comprises a highly viscous sol of glucomannan and soluble starches when reconstituted in water. The principal soluble constituent is glucomannan, a polysaccharide comprised of D-glucose and D-mannose, which is useful as an ingredient in various foodstuffs, as well as in industrial applications such as films, oil drilling fluids, and paints.
There are numerous impurities in crude, native, konjac flour, principally insoluble starches, cellulose, and nitrogen-containing materials, including proteins, many of which impurities are derived from "sacs" which encapsulate the konjac flour in the tuber.
Konjac glucomannan has been shown to readily degrade in the digestive tract. See Japanese patent application number 57185216 A2.
It would be beneficial to have a konjac glucomannan with enhanced properties to enable its use in sustained release applications.